What seemed like a deep social change in the 1990s was revealed to be a temporary accident by the year of Meetup’s founding. The idea of cyberspace made sense when the population of the internet had a few million users; in that world social relations online really were separate from offline ones, because the people you would meet online were different from the people you would meet offline, and these worlds would rarely overlap. But that separation was an accident of partial adoption. Though the internet began to function in its earliest form in 1969, it was not until 1999 that any country had...